26 
The Apogon Section 
This decorative species, which is valuable for its habit of flowering in July, when most other 
Irises except Kaempferi are past their best, is a relative of sibirica and Clarkei. All three agree 
in having the conspicuous buttresses at the base of the falls but differ in well-marked characters. 
Thus sibirica and Delavayi have hollow stems and foliage that is glaucescent on both surfaces, while 
the stem of Clarkei is solid and the leaves have a glossy upper surface. In Delavayi the standards 
resemble closely those of Clarkei in outline, but they are straight and held at an angle of 45' 
while those of Clarkei are usually curved and held almost horizontally. Moreover, the styles of 
Delavayi are not so curved as in Clarkei where the crests are carried down below the level of the 
centre of the styles. 
The seeds of Delavayi and Clarkei are very similar but the capsules may be distinguished by 
the fact that in Clarkei the sides are flat with a distinctly prominent median ridge, while in Delavayi 
a depression runs down each side. 
This species is distinctly a plant for wet ground and seems to do well in heavy soil (see also 
p. 19). 
Seedlings do not vary to any appreciable extent nor has a white form yet appeared in cultivation, 
though the eventual appearance of such a form should create little surprise. 
t XI. IVlLSONJ 
(Plate II) 
C. H. Wright, in Kew Bulletin, 1907, p. 321. 
•Bot. Mag. t. 8340 (1910). 
DISTRIBUTION. Western Hupeh and Shensi. 
West Hupeh. Fang, 1907, Wilson, 2371 (K). 
Fang Hsien, 1907, Wilson, 3072 (K). 
North Shensi. Thei-pai-shan, 1899, Giraldi (no. 6676) (B). 
Huan-ton-san, 1899, Giraldi (no. 6674) (B). 
Hua-tzo-pin, 1899, Giraldi (no. 6675) (B). 
[N.B. Forrest’s no. 1895 (West Yunnan on E. flank of Tali Range, 1906) (K) may possibly be a blue-flowered 
form of this Iris or it may be a specimen of I. chrysographes (see p. 28).] 
Diagnosis. 
/. IVilsoni Apogon ; I. sibiricae similis sed segmenta interiora oblique erecta ; capsula ovalis, 
pedicello longissimo suffulta ; semina parva, crassa ut in /. orientali. 
Description. 
Rootstock , a close growing, slender rhizome of the sibirica type. 
Leaves , linear-ensiform, acuminate, slightly glaucous on both surfaces, 2 ft. by £ in., the upper third 
drooping. 
Stem, hollow, but with thicker walls than those of I. sibirica , about equal in length to the leaves, 
bearing a terminal head of two flowers and a much reduced leaf attached about the middle. 
Spathes, two-flowered, valves narrow, acuminate, green, 2\ — 3 in. long. 
Pedicels, of unequal length, 1 — 4 in. long, solid, triangular in section. 
Ovary, £ in. long, sharply trigonal with a slight ridge on each face. 
Tube, shorter than the ovary, with many indistinct ribs. 
Falls. The broad haft has at its base two large purple-mottled flanges and bears thick broken 
veins of red-, or purple-, brown on a yellow ground. No constriction separates the haft from the ovate 
blade, which bears a semi-circular patch of bright yellow with red-brown veins, that break up into dots. 
The outer part is of a paler lemon-yellow with faint purplish veins. 
Standards. The yellow, canaliculate haft is mottled with red-brown at the edges and the narrow 
lanceolate blade with frilled edges bears faint purple veins on a pale yellowish-white ground. The 
standards are not erect but extended at an angle of 45". 
Styles , narrower than the haft of the falls, deep yellow, arched high above the falls. 
Crests, small, quadrate, overlapping. 
Stigma, a very sharply pointed tongue. 
Filaments, broad, yellow, rather shorter than the anthers. 
Anthers, cream, reaching to the stigma. 
Pollen, white. 
Capsule, short, oval, with slightly convex sides, raised far above the remnants of the spathes on 
4 — 6 in. pedicels. 
Seeds, small, thick, D- S haped, not unlike those of I. orientalis. 
Observations. 
This fine Iris has only recently been introduced into cultivation by Messrs J. Veitch & Sons of 
Chelsea, for whom Mr E. H. Wilson collected seeds. It is uncertain as yet whether a purple-flowered 
form of this Iris exists, but certain herbarium specimens seem to point to the possibility. 
